1. Field of the Invention
The present invention relates to a color scanner comprising a color monitor used for suitably setting color separation conditions of the color scanner in which color images equivalent to a color printed matter are displayed in advance on a color monitor which are reproduced by an image scanning color separating apparatus, which is generally referred to as a color scanner, forming color separation plates for multicolor printing. More specifically, the present invention relates to a color scanner comprising a color monitor capable of simultaneously displaying a plurality of images of a color original on a screen of the color monitor.
2 Description of the Prior Art
Recently, a color monitor has been used in color separation by a color scanner. The color monitor enables displaying of color images on a color CRT, which are substantially equivalent to the color images resulting from the printing. Therefore, whether the set conditions for color separation are appropriate or not can be ascertained prior to actual printing. The displaying of the color image on the color monitor is carried out in the following manner. Color separation image signals (subtractive primary colors) for recording colors such as yellow (Y), magenta (M), cyan (C), black (K) obtained from color separation scanning of the color original are converted into red (R), green (G) and blue (B) signals (additive primary colors) for display on a color CRT. Consequently, color images equivalent to the color printed matter to be reproduced are displayed on the color CRT. The method of color image display on the color monitor is disclosed in Japanese Patent Publication Gazette No. 38521/1979 (entitled "Method for Displaying Color Images") and in Japanese Patent Publication Gazette No. 822/1984 (entitled "Method of Color Monitoring Prior to Color Separation Image Scanning Recording") of the applicant of the present application.
A conventional apparatus for checking conditions for color separation of color images is disclosed in U.S. Pat. No. 4,414,636. FIG. 1 is a block diagram of a color control simulator shown therein.
Referring to FIG. 1, a conventional color control simulator comprises a pickup head 8 of a color scanner for outputting color separation signals a; a memory 52 for storing color the separation signals a obtained from the pickup head 8 in association with prescribed addresses for converting the color separation signals a to correction color separation signals b; a monitor 34 for the color scanner for displaying color images based on the correction color separation signals b; a computer 51 for controlling each of the devices; a keyboard 22 serving as an input device to the computer 51; and so on.
In the conventional color control simulator, colors corresponding to the correction color signals b written in desired addresses in the memory 52 through the keyboard 22 are displayed on the monitor 34 for the color scanner. If the displayed color is inappropriate, the color separation signal in the memory 52 can be corrected to provide an appropriate color through the keyboard 22. On this occasion, the color represented by the correction color separation signals b may be displayed on the entire surface of the monitor 34 for the color scanner, or a plurality of colors of predetermined addresses may be displayed in predetermined display areas in accordance with a predetermined order.
In the conventional color scanner, the images read by the pickup head are held one by one on a scanning drum. Therefore, in the conventional monitor for the color scanner, the color originals to be reproduced are color separated and scanned one by one. The result is displayed on the color monitor one color at a time, and it is determined whether the set conditions are appropriate or not. When a large number of color originals require processed, a long period of time is therefore required. If printed matter of high quality such as artistic printing is to be provided, the conditions for processing must be precisely set. In such case, it is preferred to check the originals one by one based on the monitor images. However, when speedy processing and lower cost are given priority over high quality as in the case of advertisement leaflets in which a plurality of color images are laid on a single sheet and not very high quality is required of each of the images, the setting of the color separation conditions before printing should be done as fast as possible in order that the color separation processing by the color scanner may be started earlier.